1. Field of the Invention
The present invention relates to a graphic meter display for a vehicle for displaying driving data by graphically displaying a dial plate and a pointer using such as a dot matrix type LCD.
2. Description of the Related Art
Japanese Published Patent Application No. 2003-262542 discloses one of a conventional graphic meter display. When the pointer on the graphic meter display is moved rapidly, many pointer images are shown as after-images. Therefore, an object of this graphic meter display is to solve the problem, and prevents a viewer from feeling a sense of incompatibility. For solving the problem, the graphic meter display displays a shadow opposed to a moving side of the pointer when a moving speed of the pointer is over a predetermined value.
Such a display technique is called a “motion blur” technique for displaying a rapidly moving object by canceling after-images, and disclosed in Japanese Published Patent Application No. 2002-15335 and No. 2003-233828.
In the graphic meter display, when a normal pointer image is displayed, the normal pointer image as a fixed pattern is drawn after determining a rotational position of the pointer image. Therefore, an image processing load is small. The motion blur pointer image is suitable for displaying a rapidly moving pointer, however, the image processing load of the motion blur pointer image is generally larger than that of the normal pointer image. Therefore, it is necessary to devise the image processing to decrease the load.
For example, as shown in FIG. 6A, when the pointer image is rotated from a pointer image a at a last frame timing to a pointer image b at a present frame timing, because the pointers a, b are rotated about the same center axis, a sector-shaped motion blur image generated by sweeping from the pointer image a to the pointer image b can be used for a realistic expression as shown in FIGS. 6A and 6B. Further, in this case, as shown in FIG. 6B, gradation can be made to be gradually thinner toward a tip of the pointer. Further, as shown in FIG. 6C, gradation can be made to be gradually thicker as a rotation speed is higher. Further, as shown in FIG. 6D, a plurality of pointer images can be overlapped with each other from the pointer image a to the pointer image b.
However, in a case of the sector-shaped motion blur pointer image as shown in FIGS. 6A and 6B, there is a problem that the image processing load for calculating a sector figure increases. Further, when making gradation, the load increases. Further, as shown in FIG. 6D, when the many pointer images are drawn, the load increases.
On the contrary, an inventor of the present invention found that because the motion blur image is a momentary display corresponding to a rapid rotation of the pointer, a realistic motion blur image is not necessary.
According to the above, an object of the present invention is to provide a graphic meter display to decrease an image processing load of displaying a motion blur image.